Formaldehyde → 1-(Tert-butoxycarbonyl)-3-[({4-[(3-chloro-2-fluorophenyl)amino]-7-methoxyquinazolin-6-yl}methyl)(methyl)amino]piperidine-3-carboxylic acid

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Reaction Steps

1-(tert-Butoxycarbonyl)-3-[({4-[(3-chloro-2-fluorophenyl)amino]-7-methoxyquinazolin-6-yl}methyl)amino]piperidine-3-carboxylic acid (Isomer 1) (400 mg, 0.71 mmol) was dissolved in 5% acetic acid in dichloromethane (25 ml) and 37% aqueous formaldehyde (5 ml) added. The mixture was stirred rapidly and sodium triacetoxyborohydride (151 mg, 0.71 mmol) added. Over a period of 5 hours a further 3 equivalents of sodium triacetoxyborohydride were added. The mixture was neutralized with saturated aqueous sodium hydrogen carbonate, the layers separated and the organic phased dried (MgSO4) and concentrated under reduced pressure. Column chromatography on silica, eluting with 10% ammonia in methanol/dichloromethane gave 1-(tert-butoxycarbonyl)-3-[({4-[(3-chloro-2-fluorophenyl)amino]-7-methoxyquinazolin-6-yl}methyl)(methyl)amino]piperidine-3-carboxylic acid (Isomer 1) (364 mg, 85%) as a white solid; 1H NMR Spectrum: (DMSO d6 100° C.) 1.27 (s, 9H); 1.47 (m, 1H); 1.86 (m, 1H); 2.01 (m, 2H); 2.30 (s, 3H); 3.30 (m, 1H); 3.44 (m, 1H); 3.63 (d, 1H); 3.74 (d, 1H); 3.81 (d, 1H); 3.88 (d, 1H); 3.96 (s, 3H); 7.19 (s, 1H); 7.25 (t, 1H); 7.40 (t, 1H); 7.65 (m, 1H); 8.22 (s, 1H); 8.41 (s, 1H); Mass Spectrum: (M+H)+ 574.5.

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